Psychoses are among the common and serious psychiatric disorders. With greater longevity, we can expect a progressive increase in the number of older psychotic patients. Antipsychotic or neuroleptic drugs are frequently prescribed for the treatment of psychotic, as well as several other severe behavioral disorders. Yet, in contrast to the large amount of literature on younger adults, there is a dearth of well controlled, comprehensive, longitudinal, prospective studies of psychosis and antipsychotics in middle-aged and elderly patients. The main goals of our CRC are to provide infrastructure support to facilitate research on late- life psychosis and antipsychotics, to test hypotheses, and to train young scientists. Over a five-year period, we will study and follow 450 subjects. These include 150 older (> 45 years old) schizophrenic patients with onset before 45; 25 late-onset (i.e., onset after age 45) schizophrenic patients, 25 late-onset delusional disorder patients, 50 younger (< 45 years old) schizophrenic patients, 50 Alzheimer disease patients with psychosis, 50 Alzheimer disease patients without psychosis, and 100 older (> 45 years old) normal controls. All the subjects will be recruited from month 4 through month 27. During the next two years, we will replace the drop- outs. The subjects will be assessed, when stable, at baseline, and then followed at least semiannually. We also plan to study the effects of neuroleptic discontinuation for at least six weeks, in approximately 50% of the neuroleptic-treated patients. The CRC will have seven Cores (1) Administrative Core for facilitating the proper conductance of research and training in the CRC. (2) Clinical Core for recruitment, diagnosis, psychiatric and medical assessment and follow- up. (3) Neurology Core for clinical neurologic evaluation, MRI analysis, and in small subsets of patients, CSF and neuropathologic studies. (4) Neuropsychology Core for a comprehensive neuropsychological assessment. (5) Psychosocial Core for evaluating each subject's support environment. (6) Motor Function Core for clinical and instrumental assessment of motor function. (7) Biostatistics/Data Management Core for services, consultation and training in experimental methodology, statistics and data management. Additionally, there will be one specialized project: We have a team of experienced, as well as young, dedicated researchers with commitment to the proposed science. We will pay special attention to the studies of women and minorities. We strongly believe that our CRC will become a national resource for investigations into psychosis and antipsychotics in late life.